In this chapter we focus on the embeddedness of participatory structures within social and political contexts, through an analysis of the “Citizen Assets Programme” (CAP) in Barcelona. This is a policy seeking to establish institutional support for the urban commons, spaces and facilities rooted in the community that are susceptible to be transferred to citizens' collectives to manage them democratically (Ajuntament de Barcelona, 2017). For doing so, we define embeddedness as the setting of policies in their social and political environment with a “productive relation to the other institutions of the democratic system” (Bussu et al. 2022a, p.3). Based on qualitative discourse analysis of official documents and 17 interviews conducted with politicians, civil servants, academics and activists between 2015 and 2021, this chapter examines the main constraints that hinder the embeddedness of participatory structures. Our findings point out the lack of an appropriate legal framework that challenges the implementation of the CAP and impairs the creation of trust in the policy. Thus, we contribute to establishing trust as one of the relevant elements in the fruitful embedding of DDG participatory structures at the local scale.